Sperm surface components will be isolated and characterized and those identified which have antigenic determinants recognized by sperm-specific and monoclonal antibodies to sperm and teratocarcinoma cells. The topographic distribution of individual antigenic surface components on the heterogeneous sperm surface will be determined by using indirect immunofluorescence procedures and monoclonal antibodies. The affects on fertilization of monoclonal antibodies to these components will be examined to relate individual antigens to sperm function and gamete interaction.